The hadith of the archangel Gabriel is of great importance because
it encompasses the foundations of Islam, Iman and Ihsan. Its status in Prophetic
tradition (sunnah) is the status of al-Fatiha (the chapter called 'The
Opener') from the remaining of the Quran. This is why it is called the mother
of all sunnah just as the Fatiha is called the mother of all Quran.
[To learn more about the significance of the Fatiha in Prayer click
here.]

In the hadith of the Gabriel (Gibreel), related by 'Umar ibn al-Khattab,
a companion of the Prophet (pbuh) and the second Caliph in Islam, the basic
aspects of the way of Muhammad (pbuh) are laid out.

One day while we were sitting with the messenger of
Allah there appeared before us a man whose clothes were exceedingly white
and whose hair was exceedingly black; no signs of journeying were to be seen
on him and none of us knew him. He walked up and sat down by the prophet.
Resting his knees against his and placing the palms of his hands on his thighs,
he said:"O Muhammad, tell me about Islam". The messenger of Allah
said: "Islam is to testify that there is no god but Allah and Muhammad
is the messenger of Allah, to perform the prayers, to pay the zakat, to fast
in Ramadan, and to make the pilgrimage to the House if you are able to do
so." He said: "You have spoken rightly", and we were amazed
at him asking him and saying that he had spoken rightly. He said: "Then
tell me about Iman."He said:"It is to believe in Allah, His angels,
His books, His messengers, and the Last Day, and to believe in divine destiny,
both the good and the evil thereof." He said: "You have spoken rightly".
He said: " Then tell me about Ihsan." He said: "It is to worship
Allah as though you are seeing Him, and while you see Him not yet truly He
sees you". He said: "Then tell me about the Hour". He said:
"The one questioned about it knows no better than the questioner."
He said: "Then tell me about its signs." He said: "That the
slave-girl will give birth to her mistress and that you will see the barefooted,
naked, destitute herdsman competing in constructing lofty buildings."
Then he took himself off and I stayed for a time. Then he said: "O Umar,
do you know who the questioner was?" I said: "Allah and His messenger
know best". He said: "He was Gibreel (Gabriel), who came to you
to teach you your religion." (Narrated by Muslim)

In this hadith, the basic foundations have been laid out. Islam
is to observe the five pillars of Islam, which are the affirmation of the Oneness
of God and the prophethood of Muhammad, as well as the institutions of prayer,
zakat, fasting and pilgrimage. Iman, or faith, requires belief in God, His angels,
books, messengers, the divine destiny of good and evil, and the Day of Judgement.
And Ihsan, or spiritual excellence, is to worship God as though you see Him,
knowing that He sees you.